Wear of nickel-titanium endodontic instruments evaluated by scanning electron microscopy: Effect of ion implantation

The present work analyzes possible increases in resistance to wear of nicke l-titanium endodontic instruments that have undergone a process of ionic im plantation. ProFile .04 taper #25 instruments were subjected to ionic impla ntation with bands of nitrogen ions of 250 KeV, currents in the order of 10 muA/cm(2), and doses of 2 x 10(17) ions/cm(2). The instruments were used t o make preparations in acrylic endodontic training blocks. Scanning electro n microscopic investigations showed that after 60 s of work inside the endo dontic training blocks nonionic implanted control instruments showed small modifications in their blades, and their tips showed the first signs of wea r. After 240 s the control instruments showed consistent signs of wear and frequent changes to their surfaces. After 240 s of use the ionic-implanted instruments did not present any significant changes in the micromorphology of their surfaces. The implanted instruments did not manifest the typical s igns of wear and did not show the surface changes that quickly affect the w orking life of untreated endodontic instruments manufactured from nickel-ti tanium.